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Tektronix 222 Repair

simonev92@...
 

Hi All!
I have a Tektronix 222 scope that doesn't work. It won't startup.
Battery is dead so I'm powering it with the external jack with a bench supply set to 14V.
When I apply power the Trigger led blink for a second and I can hear a "beep", after that nothing happens. Doing some test on the Power Supply Board (A4) I've found that the power FETs that drives the main transformer becomes very hot (the unit in this state draws about 12W of power so there's something wrong).
After some tests I've isolated the 120V line after the transformer, now the scope draws less power and the FETs stays cool but I can't make it work.
I'm using the 222A service manual which include boards schematics, they are not exactly the same but pretty similar: https://www.eserviceinfo.com/download.php?downloadstart=1&fileid=70093
In the troubleshooting procedure guide I've read that the pin 13 and 14 on the TL594 on the Power supply board should stay near 0V in normal operation, on mine they always stays at about +5V.
I think taht something isn't working properly on the power supply board but I can't find what.
Do you have any idea? Any help will be appreciated!
Thank all!
Simone


Re: Music made to be visualized on a Scope!

Tom Phillips
 

Michael,
That was much more interesting than I expected.
Thanks,
Tom


Re: Rough Shape Oscilloscopes

Oz-in-DFW
 

My experience is that the vast majority of the "spoilage" happens in the chain after the stuff is officially retired. It's put on a pallet and handled by people who mostly process Gaylords of waste material or 55 gallon drums.


Re: Rough Shape Oscilloscopes

Randy.AB9GO
 

We tried to give surplus network equipment to the Cincinnati Public Schools
so they could set up a computer lab and teach the students computer
networking. They were all for it UNTIL they found out the equipment was
used. They only accepted NEW equipment donations. Same story from the
private schools. After it sat around for for years we sent 18 pallet loads
of equipment to the recyclers.

Randy AB9GO.

This message sent to you from my mobile device via speech-to-text
technology.


Re: Rough Shape Oscilloscopes

stevenhorii
 

Bill,

I have seen a transition. I work at a major academic medical center. They
used to have a policy of letting employees take home computers that were
working but out of their current specifications. They pulled the hard
drives so no PHI was left in the machine. Now, they won't even let someone
take a computer for their own use even if the hard drives are pulled. When
I asked why, or why they could not be donated to another organization that
could use them, they just answered that it was a new policy. I know the
folks in IT and they have let me take machines for my own use after they
pulled the drives and removed the property tags. I refurbed them, installed
a hard drive and OS and gave them to folks who could not afford a machine.
They have let me take other stuff - there was a surgical microscope that
was sitting outside the OR with a "discard - non-repairable" tag on it.
They said I could have it as long as it did not come back. It turned out
that the fiber optic illuminator was bad - just a bad variable transformer
in it. The company repair guy had told them he could not get the part. The
microscope was perfectly fine. I wound up swapping it to a surplus dealer
for some test equipment (a nice HP counter and some Tek 7000-series
plug-ins). There is an awful lot of stuff that just goes out in the
dumpster, though there are separate bins now for "e-waste". Some
universities have property disposal sales offices. I went to one at
Stanford (though this was years ago). They had a couple of Tek scopes, but
at the time, I had more of the 500-series than I hsd space for and shipping
would have been more than they were asking for them, so I didn't buy them.
The one thing I should have bought was an Imsai computer. Fully-loaded and
working. They were asking $100. Just do a search on eBay and see what they
sell for now.

Steve H

On Sat, Apr 11, 2020 at 11:14 PM william_b_noble <william_b_noble@...>
wrote:

Your point about discards is right on. And, sadly, in many companies,
policy forbids employees from buying surplus or even bidding at surplus
auctions, so you can watch the valuable stuff leave but you can't do
anything about it to save it or even to redirect it to an organization that
needs it. Presumably this is to prevent fraud. Not sure it's worth it
though

Regards, Bill Noble
www.wbnoble.com<http://www.wbnoble.com/>





Re: Rough Shape Oscilloscopes

william_b_noble
 

Your point about discards is right on. And, sadly, in many companies, policy forbids employees from buying surplus or even bidding at surplus auctions, so you can watch the valuable stuff leave but you can't do anything about it to save it or even to redirect it to an organization that needs it. Presumably this is to prevent fraud. Not sure it's worth it though

Regards, Bill Noble
www.wbnoble.com<http://www.wbnoble.com/>


Re: How to Remove Knobs

Rich Frahm
 

Thanks for all the ideas guys! I did break the first one I tried to remove but the second one came off ok with some heat. Here is the first prototype: https://drive.google.com/file/d/1rW9zR2inVmAxY-iVq69uUiHVP6kOtX6l/view?usp=sharing I don't know why the top half is so rough...I've printed knobs before that came out great. Although not this small. I was going to try to put in the "spring" pieces, but the fit is so snug that I don't think I have to. If I use them a while and they loosen up then I'll see if I can change them to put the spring pieces in, but I really don't think it'll be necessary.

Rich


Re: How to Remove Knobs

Tony Fleming
 

Harvey, you are right, one can make a puller and or even get en inexpensive
faucet handle puller - they cost like $7 or so at any lumberyard - that is
the one I use.
Look here what you can get for $5.00 :
https://www.harryepstein.com/valve-faucet-handle-puller.html?gclid=CjwKCAjw1cX0BRBmEiwAy9tKHj_iIPn7xAMtTdDHXjyqs_iPuvRoTVieEqTW1AbDGsZ_z9xy595ysBoCZsUQAvD_BwE
One can improve it by putting a double sticking tape and attach thin
leather or something that makes it less slippery and soft so you don't
scratch the knob on the bottom. But that is sometimes too tight to fit, if
the knob is very close to the panel.
You all have a great EASTER!

On Sat, Apr 11, 2020 at 6:04 PM Harvey White <madyn@...> wrote:

Assuming that they're press fit ONLY, make two identical 2 tined ramps,
where the distance between forks will accommodate the shaft and nut (if
any). Place one as far in as it will get. That protects the panel.
Put the other one in from the other side and slowly compress them, that
ought to wedge the knob off.

Another option would be to make a knob puller that looks a bit like the
gear pullers you can buy. You'd have to have a "platform" that would
brace against the front panel and pull out.

I like the two wedges better. (something similar is used for removing
jacobs chucks from JT tapers in machining).

Harvey


On 4/11/2020 10:57 AM, Rich Frahm wrote:
I am missing 2 knobs on my Tektronix 2430A...you can see one of them in
the upper right of this photo:
https://drive.google.com/file/d/1DnL8WGdCWLjQ1aA9dq9oKvmY-p2O8ZOe/view?usp=sharing

I do 3D printing and want to see if I can make new ones so would like to
remove one to inspect it. What's the proper way to remove these knobs?

Thanks!

Rich






Re: Rough Shape Oscilloscopes

Greg Muir
 

Picked up a $20k recent model microwave frequency counter from the local AF base on surplus for less than $200. It was out-of-warranty model that had a “unserviceable” tag and was in nearly new (pristine) condition. The “unserviceable” problem? A dirty edge connector on the power supply that made the counter occasionally intermittent.

Greg


Re: Rough Shape Oscilloscopes

Tony Fleming
 

Have you tried to sell the stuff on eBay?
There are nonprofit organisations, clubs and schools, yet even many individuals, who would take these gems and use them for something good!
Our club received about 100 nice laptops - we had to do a secure reformat and reinstall Windows 10... but now we have laptops to use when we teach computers, 3D printers, Arduino....
In Lincoln, NE we have recycle station that takes the equipment and sell them for $$ and if they don't sell, they are recycled by companies that recover gold and other parts that can be reused.
I'm sure there should be also something like in every city that has 2K or more people living there.
Myself, I don't like to dump stuff and I recycle or make a working computer and give it to people less fortunate.
There are people in these days who have no computer at home! These "older PC's and laptops" can be reused and given to them to use.
Why isn't there someone who will find people or organisations that takes this stuff and try to reuse or make even money from sales this can create.
The money is than used for helping people or organisations, that need money!


Re: Rough Shape Oscilloscopes

Brad Thompson
 

Hello--

An acquaintance who worked at an instrument-leasing company told me
about one of their 453 scope loaners that (mis)spent its life adjacent to a
plating tank. The scope's innards were corroded beyond repair.

73--

Brad  AA1IP


Re: Rough Shape Oscilloscopes

Clark Foley
 

Apart from the dumpster finds with an old beauty face down in the debris, I am reminded of one story from my days working in the Tek 7000 series marketing group. One of my colleagues, Eric, went to visit a major contractor for the military and was told by the customer that 7000 series amplifiers and the probe were very unreliable. Eric was surprised and asked if he could discuss the issue with some of the metrology technicians using the equipment. After 20 or 30 minutes of suffering the abuse of the department manager, the manager agreed to let him discuss the reliability issue with the technicians.

As the two entered the metrology lab and started down an aisle flanked by the technicians. One technician asked another across the aisle if he could borrow one of the 7000 series amplifiers. The friendly technician obliged by swinging the amplifier to him using the attached probe as a tether to protect the plugin from hitting the floor (think Tarzan swinging from a vine). The manager abruptly discontinued his tirade and Eric's visit was much more comfortable.

I am certain that it was not a common occurrence at most places but I remain puzzled and impressed by the abuse delivered to this equipment and yet most of the time you can still salvage or repair the beasties!

Clark


Re: Artek Manuals

ArtekManuals <manuals@...>
 

Garry

Which manual are we talking about?

Dave

On 4/11/2020 7:28 PM, Gary Robert Bosworth wrote:
I don't mind the schematics being copied in Black & White, but I would
prefer the circuit boards to be done in gray scale. Any overlay writing
on the circuit boards becomes illegible against the background when the
boards are done in strictly black & white..

On Sat, Apr 11, 2020 at 3:21 PM Bruce Lane <@kc7gr>
wrote:

Most definitely. I've been a very happy customer for many moons.
Dave
does some of the clearest scans I've ever seen.


On 11-Apr-20 14:56, Bill via groups.io wrote:
Are the Artek manuals full page? Some online manuals are very hard to
read and if you enlarge them they go off the page.
Bill


--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)



--
Dave
Manuals@...
www.ArtekManuals.com
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Re: Rough Shape Oscilloscopes

Gary Robert Bosworth
 

Many times, these oscilloscopes are auctioned off on pallets and they
really were abused by forklifts. The shipping and receiving guys are not
technically astute, and they think the oscilloscopes are to be sold off for
scrap metal.

On Sat, Apr 11, 2020 at 4:25 PM Randy.AB9GO <@AB9GO> wrote:

When equipment is sent to the recycling center we toss our surplus in a
Gaylord box. And I mean toss. Ethernet switches that cost $6000.00 a few
years ago are thrown in like trash. You can't even get $20 on eBay for
them. PCs, laptops, printers, medical equipment (I work at a hospital)
thrown right in the Gaylords. Why be gentle with equipment with little to
no value?

This message sent to you from my mobile device via speech-to-text
technology.



--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247


Re: Artek Manuals

Gary Robert Bosworth
 

I don't mind the schematics being copied in Black & White, but I would
prefer the circuit boards to be done in gray scale. Any overlay writing
on the circuit boards becomes illegible against the background when the
boards are done in strictly black & white..

On Sat, Apr 11, 2020 at 3:21 PM Bruce Lane <@kc7gr>
wrote:

Most definitely. I've been a very happy customer for many moons.
Dave
does some of the clearest scans I've ever seen.


On 11-Apr-20 14:56, Bill via groups.io wrote:
Are the Artek manuals full page? Some online manuals are very hard to
read and if you enlarge them they go off the page.
Bill


--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)



--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247


Re: Rough Shape Oscilloscopes

Randy.AB9GO
 

When equipment is sent to the recycling center we toss our surplus in a
Gaylord box. And I mean toss. Ethernet switches that cost $6000.00 a few
years ago are thrown in like trash. You can't even get $20 on eBay for
them. PCs, laptops, printers, medical equipment (I work at a hospital)
thrown right in the Gaylords. Why be gentle with equipment with little to
no value?

This message sent to you from my mobile device via speech-to-text
technology.


Re: Rough Shape Oscilloscopes

Harvey White
 

Once bought a DC5010 counter from a good surplus place.  It didn't work.  After a bit of detective work, I found that two or three connections had been cut (very deliberately, thank you), right at the top of the edge connectors.

Worked perfectly after the repair.

Harvey

On 4/11/2020 11:58 AM, Jeff Kruth via groups.io wrote:
Two things about equipment damage:

First one is many times irritated technicians who want to vent, or want newer gear, damage the older stuff, so that they can get rid of it.Once got a lot from NASA, all '60's -'70's vintage gear (this was in 1979), every piece of the 40 items or so was red tagged, meaning BAD, BER. Only a few pieces were actually defective with minor issues, all the rest was fine. They wanted new stuff!
Second issue is the people in charge of excessing equipment, both gov't and private companies, just really dont care about it. I mean REALLY dont care about it, it aint their stuff. They drop it, crash it together on pallets, breaking knobs and bending stuff, cut cords off, leave it outside, etc.  I once bought 45 7704 scopes that came from Andrews AFB where they had sat in the rain outside for 6 months. Paid <$10.00 ea for them. With plug-ins. Probably shouldnt have bought them as they were a lot of work to clean up and get going. About a 50% recovery rate. Sold the rest off to a well known mail order surplus house.
YMMVJeff Kruth

In a message dated 4/11/2020 10:42:49 AM Eastern Standard Time, @satbeginner writes:
I agree, I just cannot understand what people do with (their?) tools/equipment?
(Probably not theirs, so they don't appreciate the value)

My statement:

Tools do NOT break by themselves,

They're broken by the weirdos using them...

And it starts with using a screwdriver as chisel...




Re: Artek Manuals

Michael W. Lynch
 

I have purchased both the CD's and the online downloads. Their work is first rate. The only thing better is an actual paper manual and these are most of the time ridiculously overpriced. I have never had a problem with these manuals in either format. Buy with confidence.

--
Michael Lynch
Dardanelle, Arkansas


Re: Rough Shape Oscilloscopes

Harvey White
 

Bad condition comes in a bale held together by packing wire and structural plastic.

Harvey

On 4/11/2020 10:53 AM, Brian via groups.io wrote:
I have seen on Ebay scopes that have smasked bezels around the crt and broken knobs etc , to say nothing of scratches and dents in the cabinet -- described as GOOD CONDITION ??????
I wouldnt have the nerve to say that , let alone try to sell it for the price some ask

Brian


On Saturday, 11 April 2020, 15:42:50 BST, satbeginner <@satbeginner> wrote:
I agree, I just cannot understand what people do with (their?) tools/equipment?
(Probably not theirs, so they don't appreciate the value)

My statement:

Tools do NOT break by themselves,

They're broken by the weirdos using them...

And it starts with using a screwdriver as chisel...





Re: How to Remove Knobs

Harvey White
 

Assuming that they're press fit ONLY, make two identical 2 tined ramps, where the distance between forks will accommodate the shaft and nut (if any).  Place one as far in as it will get.  That protects the panel.  Put the other one in from the other side and slowly compress them, that ought to wedge the knob off.

Another option would be to make a knob puller that looks a bit like the gear pullers you can buy.  You'd have to have a "platform" that would brace against the front panel and pull out.

I like the two wedges better.  (something similar is used for removing jacobs chucks from JT tapers in machining).

Harvey

On 4/11/2020 10:57 AM, Rich Frahm wrote:
I am missing 2 knobs on my Tektronix 2430A...you can see one of them in the upper right of this photo: https://drive.google.com/file/d/1DnL8WGdCWLjQ1aA9dq9oKvmY-p2O8ZOe/view?usp=sharing

I do 3D printing and want to see if I can make new ones so would like to remove one to inspect it. What's the proper way to remove these knobs?

Thanks!

Rich